Portable stair



Nov. 27, 1923. 1,475,777

J. L. BALLENGER PORTABLE STAIR Original Filed Sept. 27. 1921 2 Sheets-Sheet l J? 3 ll R ,H 7 8 l tfafinlja/zzei g er INVENTOR ATTO R N EY Nov. 27, 1923.

J. L. BALLENGER PORTABLE STAIR Original Filed Sept. 27 1921 2 Sheets-Sheet 2 J5 J5 J5 I K l f I l 7L 7 1 J5 @knLfiaZZezyer MENTOR ATTO RNEY Patented Nov. 27, 1923. p

. UNITED STATES JOHN L. BALLENGER, OF GREENVILLE, SOUTH CAROLINA.

PORTABLE STAIR.

Application filed September 27, 1921, Serial No. 503,578. Renewed June 28, 1923.

J '0 all whom it may concern:

Be it known that I, JOHN L. BALLENGER, a citizen of the United States, residing at Greenville, in the county of Greenville and State of South Carolina, have invented new and useful Improvements in Portable Stairs, of which the following is a specification.

The object of my said invention is the provision of a stair for inside or outside use constructed in such manner that it may be shipped or moved in knock down state and may be set up without the employment of skilled labor, and this in such manner that the steps are locked in the stringers and the risers are locked in the steps without liability of the stringers, steps or risers casually moving when in use.

The invention also contemplates the provision of improved means for fastening the stair as aunit in position, and when the stringers are formed of concrete, metallic reinforcements in the stringers will be utilized as an anchoring or fastening means of the stair.

To the attainment of the foregoing, the invention consists in the improvement as hereinafter described and definitely claimed.

In the accompanying drawings, forming part of this specification Figure l is a perspective illustrating my novel stair construction as set up ready for use.

F igure2isavertical transverse section of the same. 1

Figure 3 is a vertical section taken through one of the stringers and showing the metallic reinforcement therein.

Figures 4, 5 and 6 are detail views of one of the steps comprised in the improvement.

Similar numerals of reference designate corresponding parts in all of the views of the drawings.

My novel stair construction is made up of several elements all of which are preferably formed of concrete though I would have it distinctly understood that it is within the purview of my invention to form the said elements of wood or other material compatible with their purpose.

Among the elements of the stair are stringers 1 which I will describe as being formed of concrete, that being the preferahis material. Each of the stringers 1 ineludes a body of concrete and a metallic reinforcement 2 embedded in the concrete body and extending from the rear end to the for-' ward end thereof. At its rear end the metallic reinforcement 2 terminates in a pin 3 that extends from the rear end of the stringer and is designed to be disposed in a wall or the like with a view to fixing the rear end of the stringer with respect to the wall. The forward end of the reinforcement 2 is formed into a hook 4, disposed in front of the forward end of the stringers as illustrated. In its upper rear corner the stringer is provided with a recess 5, and at intervals in the length of its upper edge the gitudinal groove 11 to receive the upper edge a of a riser 10, and is also provided in its rear upper corner with a rabbet 12. Below its rabbeted portion each step 9 is provided with a pendent rib 13 which is preferablyof rectangular form in cross section as are also the recesses 5, 6 and 7.

In assembling the elements of my novel stair, the stringers 1 are first arranged in appropriate spaced and parallel position, their pins 3 being embedded and secured in a wall or other convenient support. The steps 9 and the risers 10 are then relatively arranged and interlocked as illustratedi. e., the steps are arranged on the stringer portions 8 and so that the pendent ribs 13 rest in the recesses 5, 6 and 7, and the risers 10 are arranged with their upper edges in the grooves 11 of the steps. The lowermost riser 10 is seated in the hooks 4 of the stringers, while the other risers 10 are disposed in the rabbets 12 of the upper steps. From this it follows that the stringers, steps and risers are strongly held together of themelves and without the assistance of extraneous elements. It also follows that when it is desired, the stair may be expeditiously and easily taken apart and moved from one place to another after which it may be as readily set up for use in a new location.

In addition to the characteristics de scribed, the steps 9 are provided in the undersides of their pendent ribs 13 with recesses 15 to receive portions of the strin ers 1. This provision manifestly will prec udc casual endwise movement or creeping of the steps relatively to the stringers.

have entered into a detailed description of the construction and relative arrangement of the parts embraced in the present and preferred embodiment of my invention in order to impart a full, clear and exact understanding of said embodiers of plastic material, each stringer having embedded therein a metallic reinforcement which terminates at its rear end in an extended-pin and at its forward end in an extended hook, and steps and risers interlocked with each other and the I stringers and detachably associated with each other and the stringers, the interlocking of the lowermost riser with the stringers being effected by the seating of said riser in the hooks of said metallic reenforcement. K 2. A stair construction comprising stringers ofplastic material, each stringer having embedded therein a metallic reinforcement which terminates at its rear end in an extended pin and at its forward end in an extended hook, and steps and risers interlocked with each other and the stringers and detachably associated with each other and the stringers, the stringers having step supporting portions and recesses at the rear end of said portions, and the steps having recesses back of said portions, risers, and

steps, each step having a groove in the underside of its forward portion to receive the upper edge of a riser, and each step also having a rabbet in its rear upper corner to seat the lower edge of a riser, and further having below the rabbeted portion a pendent rib to seat in one recess of the stringer.

4. A stairconstruction comprisin stringers, and steps and'risers supporte by the stringers and detachably associated with each other and with the stringers, the steps and stringers, and the risers and steps, having interlocked portions, and the stringers being provided at their upper ends with securing pins and at their lower ends with hooks extended from said ends and receiving the lower edge of the lowermost riser.

5. A stair construction comprisin stringers, and steps and risers supporte by the stringers and detachably associated with each other and with the stringers, the steps and stringers, having interlocked portions to hold the steps against forward movement, and the risers and steps having interlocked ortions, and the steps being provided with rear pendent ribs and recesses in said ribs, receiving portions of the stringers, whereby the steps are held against endWise movement relative to the stringers.

In testimony whereof I ail-ix m signature.

JOHN'L. BALL NGER. 

